We have terrible drainage and clay soil and even though we put the run and coop where we thought it may be the driest it is still a muddy gooey mess in the run. Does the mud pose any harm to the chickens? Can we add buckets of sand to help with the mess? Will sand hurt them? Any other ideas would be great. We did cover half the run with a slanted tarp roof and that helps a bit but it is very rainy here in washington state.